When Nifty surges or Bank Nifty stalls, the first question a trader asks is simple: is anyone actually behind this move? Until now, that question was hard to answer on an index chart.
The problem with index volume
You cannot buy or sell the Nifty 50 index itself. It is a calculated value of 50 stocks. Because nobody trades the spot index directly, it has no traded volume of its own, and most charts show its volume pane empty, delayed, or borrowed from the futures contract.
That leaves a gap. Price on the index chart, but no reliable read of participation behind it.
What is new on SAHI
SAHI now builds index volume from the bottom up. It adds together the live traded quantity of every stock in the index, candle by candle, and refreshes it several times a second. The index gets a real volume figure, and with it, every volume-based indicator works on the index chart just as it does on a stock.
The four indicators
1. Volume
The total traded quantity of the index in each candle, in real time. It measures participation. A breakout candle on clearly rising volume has many traders behind it; the same candle on thin volume does not.
2. VWAP (Volume Weighted Average Price)
The average price the index has traded at through the session, weighted by volume. It resets every day. Institutions use it as an execution benchmark; traders use it as the day's fair price. Above VWAP, buyers are in control; below it, sellers are.
3. OBV (On-Balance Volume)
A running total that adds a candle's volume when it closes higher and subtracts it when it closes lower. It shows whether volume is flowing with price or against it.
4. PVT (Price Volume Trend)
Like OBV, but each candle's volume is weighted by the percentage size of its price move. Small moves count for little, large moves count for more. It gives a smoother read of how strongly volume supports the trend.
| Indicator | What it shows | Best for |
|---|---|---|
| Volume | Participation in each candle | Grading breakouts and retests |
| VWAP | The session's volume-weighted fair price | Intraday bias and pullback entries |
| OBV | Running flow of volume by direction | Spotting when heavy volume flips sides |
| PVT | Running flow weighted by the size of the move | Confirming or questioning a trend |
How to use them together
Let price action find the setup, and let volume grade it. Here is the same sample session, read in four steps:
- Up
- Down
- VWAP
- All morning, price stays below VWAP. Sellers are in control.
- A candle breaks out of the morning range and closes above VWAP on the heaviest volume since the open.
- The pullback returns to VWAP on light volume and holds.
- Price trends above a rising VWAP for the rest of the session.
Level on the price chart, a close beyond it, volume clearly above recent bars, in the direction of the VWAP bias, with OBV/PVT confirming. The more of these line up, the stronger the read.
What makes it different
- Real-time refresh. Index volume on SAHI refreshes several times a second, so you see participation build while the candle is still forming.
- Both exchanges. Coverage spans NSE and BSE indices, from Nifty, Bank Nifty and FinNifty to Sensex.
- Built from constituents. The volume is calculated from the live trades of the stocks inside each index, not taken from a summary feed.
The point is not speed for its own sake. It is seeing conviction while it builds, not after it has gone.
Questions
Is this the same as Nifty futures volume?
No. Futures volume counts contracts in the futures market. SAHI's index volume adds up the traded quantity of the stocks inside the index.
Which indices are covered?
Major NSE and BSE indices, including Nifty 50, Bank Nifty, FinNifty and Sensex.
How do I add these indicators?
Open an index spot chart on SAHI, tap the fx icon on the chart toolbar and add Volume, VWAP, OBV or PVT. Each of OBV and PVT opens in its own pane.
Learn to read them properlyOur free five-chapter course walks through each indicator with charts, worked examples and a session checklist.
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